<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>login</title>
</head>
<body>
    <h1>login</h1>
    <h3 th:text="${msg}" style="color: red"></h3>
    <hr>
    <form action="/login" method="post">
        username: <input type="text" name="username"><br>
        password: <input type="password" name="password">
        <input type="submit" value="提交">
    </form>
</body>
</html>